Does Social Support Moderate the Relationship between Frailty and Functional Ability Trajectory Among Community-Dwelling Older Adults?

Abstract Background Functional ability is the important prerequisite to live independently and achieve aging in place, which depends on the complex interaction of intrinsic and extrinsic factors. Identifying the trends and influencing factors of functional ability would contribute to the accurate assessment and intervention of geriatric health. This study aimed to disentangle the moderating effect of 3 types of social support, namely objective support, subjective support, and support utilization, on the relationship between frailty and functional ability trajectories. Methods This was a secondary analysis using data from a prospective 3-wave study with a sample of 777 Chinese community-dwelling older adults. Social support was assessed using the Social Support Rating scale. Frailty was assessed using the FRAIL scale. Functional ability was measured by the Lawton Instrumental Activities of Daily Living scale. Latent growth curve models were implemented to test their relationships. Results Objective support but not subjective support or support utilization moderated on the relationship between frailty and functional ability slope. Functional ability decline over time was buffered by objective support among robust individuals but exacerbated among (pre)frail individuals. Conclusions The moderating effect of social support on the relationship between frailty and functional ability trajectory varies by support types, which reminded that social support may be a promising intervention target to maintain functional independence for frail individuals, opening up a new perspective on social support in the field of disability prevention. Effective interventions should particularly address objective support in conjunction with empowering the frail older population to optimize the trajectory of functional ability.